The human visual system is a complex system with a great ability to absorb vast amounts of information originating in many varying formats, including visual displays. Visual displays are found in varying sizes and forms in today's world, displaying many types of information, from large visual display screens announcing scheduling information found in airports, to small visual displays, such as those incorporated into pocket calculators. Of current concern is the display of images when utilizing teleconferencing technology and teleconference display devices.
Face-to face conversation is universally recognized as the preferred form of human communication. In a typical teleconferencing system, a pair of terminals, each with a video camera and a video display device, a microphone, and a speaker, are connected by a telecommunication link to permit face-to-face communication at a distance. However, such systems known today while utilizing this face-to-face communication standard have failed to address that communication is best when video conference communicants have eye-contact with each other.
In a typical videoconferencing terminal, the video camera and the video display are not in line with one another. The communicant has to either face the camera or the display, resulting typically in an image that captures the communicant's face staring off into space. No eye-contact is possible with the communicant during the teleconference because of the need to have eye-contact with the display.
Prior attempts to solve this problem have utilized a half-silvered mirror in front of the display terminal with a camera positioned behind it. The problem with this arrangement is that the video display no longer offers a front-surface view, but an image that is recessed into the terminal. Accordingly, the sense of immediance, thus presence is lost.
Other attempts to create eye contact by placing a video projection source behind a liquid crystal screen and in-line with the video camera have been suggested. This type of system operates in two modes, an image capture mode and an image display mode. During the image display mode, the liquid crystal screen is translucent and serves as a rear-projection screen to display the image of the distant communicant. During the image capture mode, the liquid crystal screen is transparent and the video camera detects the image of the local communicant, or participant. This type of system requires a vast amount of space for the projection display and typically requires conference facility modification. This modification requirement increases the cost of teleconferencing substantially. In addition, this type of system can only be utilized with projection displays and is not applicable to CRT displays, TFT liquid crystal displays, field emission displays, and the new emerging plasma displays.
Thus, there is a need for a teleconferencing system including a display terminal that includes the ability to display an image and transmit an image while maintaining eye-contact between the system communicants.
Accordingly, it is highly desirable to provide for a teleconference system including a display terminal that provides for the maintenance of eye-contact between the local and distant communicants.
It is a purpose of the present invention to provide for a new and improved teleconference system including a display terminal that provides for the in-line transmission of images, thus achieving eye-contact between a distant and local communicant.
It is a further purpose of the present invention to provide for a new and improved teleconference display terminal that includes optical properties so as to serve the local communicant as a mirror to reflect the communicants image toward a video transmission camera, and as a display screen to display the distance communicant's image.
It is yet still another purpose of the present invention to include a blazed grating on a surface of a display terminal thereby providing for the reflectance of a local communicant's image to a video camera positioned at an angle thereto, while simultaneously serving as a display screen to display the image of a distant communicant.